These functions fail with -EINVAL if the corresponding callbacks
are not implemented.  Change them to return -ENOSYS as it is more
appropriate for unimplemented callbacks.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
                                codec->cache_ops->name, codec->name);
                return codec->cache_ops->init(codec);
        }
-       return -EINVAL;
+       return -ENOSYS;
 }
 
 /*
                                codec->cache_ops->name, codec->name);
                return codec->cache_ops->exit(codec);
        }
-       return -EINVAL;
+       return -ENOSYS;
 }
 
 /**
        }
 
        mutex_unlock(&codec->cache_rw_mutex);
-       return -EINVAL;
+       return -ENOSYS;
 }
 EXPORT_SYMBOL_GPL(snd_soc_cache_read);
 
        }
 
        mutex_unlock(&codec->cache_rw_mutex);
-       return -EINVAL;
+       return -ENOSYS;
 }
 EXPORT_SYMBOL_GPL(snd_soc_cache_write);
 
        }
 
        if (!codec->cache_ops || !codec->cache_ops->sync)
-               return -EINVAL;
+               return -ENOSYS;
 
        if (codec->cache_ops->name)
                name = codec->cache_ops->name;